(1) Field of the Invention
The present invention relates to fan packs and, more particularly, to a fan pack in use in cooling electronic equipment mounted in an equipment frame.
(2) Background Art
Cooling modules sometimes called fan packs are very well known to those skilled in the art. In this regard, U.S. Pat. No. 3,967,874 to Calabro teaches an apparatus employing a high velocity centrifugal fan for uniformly cooling an array of printed circuit boards in a card holding file. The centrifugal fan is positioned at one side of the card file and a duct is provided below the card file connected to an output of the fan to duct cool air from the fan to a lower edge of each of the cards provided within the card file, thus to cool the cards. A screen positioned within the duct produces turbulence to reduce the velocity of air flowing in the duct and to uniformly direct the air flow to the printed wiring cards.
U.S. Pat. No. 4,502,099 to Manes et al. teaches a cooling system for electronic components wherein an air supply housing with two openings cooperates with a manifold including one opening to distribute cooling air from the air supply housing through the manifold to a card cage while the manifold is closed for normal operation and also while the manifold is extended to allow maintenance of the electronic components. When the manifold is extended for maintenance, air flows into the manifold through a first opening in the housing while the second opening is blocked by a flapper which swings down over the second opening to prevent the escape of air therethrough.
Additionally, U.S. Pat. No. 3,249,038 issued to Johnson and U.S. Pat. No. 4,385,552 issued to Nabben, both teach the use of shutters to prevent back drafts in air intake and exhaust ventilation fans.
Finally, U.S. Pat. No. 4,493,341 issued to Wieland teaches the use of multiple control vanes within a distributor unit for adjustment of the distribution of volume flows from two source openings to three outlet connections.
The above arrangements, while operating generally satisfactorily for their intended purposes, have been found to be nonapplicable to the task of cooling electronic circuitry mounted in a vertically oriented equipment frame.